18F-FDG PET/CT as predictor of tumour biology and prognosis in epithelial ovarian carcinoma

OBJECTIVE

To investigate the relationship between maximum standardised uptake value (SUVmax) of ovarian lesions and histopathology subtypes, and their involvement in the response and prognosis of patients with epithelial ovarian carcinoma (EOC).

MATERIAL AND METHODS

A retrospective analysis of 31 patients with EOC and ¹⁸F-FDG-PET/CT before treatment, including an assessment of the SUVmax of ovarian lesion. Histopathological diagnosis and follow-up was performed. A study was made on the relationship between the SUVmax and histological type (type I and II) and tumour stage, as well as the role of various parameters (SUVmax, histology, stage) on the patient outcomes (complete response [CR], overall survival [OS], disease-free survival [DFS], and disease-free [DF] status, at 12 and 24 months).

RESULTS

The medium SUVmax in type I lesions was lower than in type II (6.3 and 9.3, respectively; P=.03). A 7.1 cut-off was set for SUVmax in order to identify type II EOC (sensitivity: 77.8%, specificity: 69.2%; AUC=0.748; P=.02). No significant relationship was found between tumour stage and SUVmax. CR was more common in early stages; relative risk (RR) of 1.64; P=.003, as well as in type I tumours and a lower SUVmax. Tumour stage was decisive in DFS (P=.04), LE24m (0.07) and OS (P=.08). Longer DFS and a higher percentage of DF 24m were observed in type I tumours (RR: 1.32; P=.26).

CONCLUSIONS

SUVmax was related to EOC histology, so could predict the response and prognosis of these patients. No association was found between glycolytic activity of the primary tumor with the response and prognosis.

Incidental pathologic extracardiac uptake of (99m)Tc-tetrofosmin in myocardial perfusion imaging: Importance of patient background evaluation

(99m)Tc-tetrofosmin single photon emission computed tomography ((99m)Tc-tetrofosmin SPECT) has an important role in the assessment of coronary artery disease. Despite being its main indication, this study does not only evaluate myocardial perfusion, but much more. Moreover, during the SPECT acquisition, the field area covered includes many important organs of the thorax and abdomen, so extracardiac abnormalities can be observed. The correct etiologic diagnosis of them is only possible if we understand how (99m)Tc-tetrofosmin works and make a comprehensive investigation of the clinical history of the patient.

[Implementation of a quality management system according to the UNE-UN-ISO 9001:2008 standard in a nuclear medicine department]

OBJECTIVE

To describe the process of implementing a quality management system according to UNE-EN-ISO 9001:2008 standard in a Nuclear Medicine Department.

MATERIAL AND METHOD

In February 2008, the committee on internal quality of the Department was established, naming a responsible physician. The general operating plan was drawn up, following the requirements established by the ISO 9001:2008 standard. It defined the scope of the standard, defining, preparing and transcribing the various activities of our Department. Four training sessions were carried out.

RESULTS

A total of nine general and two specific procedures were documented in which all the activities performed in our Department were included. Personnel records of each worker were created, including their profiles and training plan. A record of the equipment and service providers was created, as well as issues with the latter. Satisfaction surveys were obtained from external (patients) and internal customers (faculty applicants). Targets for improvement and activity markers were established. Two audits were performed to complete the process, one internal and one external. The Department was accredited in April 2010.

CONCLUSION

The quality accreditation process is a tool that requires reflection on how we do things and how they can be improved. It makes it possible to measure what we do, to analyze and introduce improvement measures, and therefore, to achieve a higher level of quality in the service we provide our customers. The involvement of the Department workers with a commitment to team performance was essential.

18F-FDG semi-quantitative parameters and biological prognostic factors in locally advanced breast cancer

AIM

To analyse the correlation between (18)F-FDG uptake assessed by PET/CT in locally advanced breast tumours and histopathological and immunohistochemical prognostic factors.

MATERIAL AND METHODS

Thirty-six women with breast cancer were prospectively evaluated. PET/CT was requested in the initial staging previous to adjuvant chemotherapy (multicentric study). All the patients underwent an (18)F-FDG PET/CT with a dual-time-point acquisition. Both examinations were evaluated qualitatively and semiquantitatively with calculation of SUVmax values in PET-1 (SUV-1) and in PET-2 (SUV-2) and the percentage variation of the standard uptake values (retention index) between PET-1 and PET-2. Clinical and metabolic stages were assessed according to TNM classification. The biological prognostic parameters, such as the steroid receptor status, p53 and c-erbB-2 expression, proliferation rate (Ki-67), and grading were determined from tissue of the primary tumour. Metabolic and biological parameters were correlated.

RESULTS

A positive relationship was found between semiquantitative metabolic parameters and biological parameters. SUV-1 and SUV-2 values did not show significant statistical correlation (p<.05) except for the clinical tumour size. About the biological parameters, retention index showed the best results with positive and significant relation (p<.05) with estrogen and progesterone receptor status and Ki-67. Isolated SUV values did not show significant relation to these parameters.

CONCLUSION

Retention index showed the best relation with biological parameters compared to isolated SUVmax values. These data suggest that SUV change over time is a prognostic marker.

Study of the sentinel node in endometrial cancer at early stages: preliminary results

AIM

To investigate the applicability of the sentinel lymph node biopsy technique in early stages of endometrial cancer.

MATERIAL AND METHODS

A prospective study that included consecutive patients with a histological diagnosis of clinical state I endometrial carcinoma was performed. Two doses of 2 mCi (74 MBq) of (99m)Tc-albumin nanocolloid were injected in the uterine cervix, and planar and SPECT-CT images were obtained at one hour, and at 24 hours if no migration of the tracer was observed. Methylene blue dye was also injected into the cervix immediately prior to the surgery. A gamma probe was used during the surgical procedure for sentinel lymph node identification. In all cases, a hysterectomy, double adnexectomy and pelvic lymphadenectomy were performed, carrying out a histological analysis (hematoxylin-eosin) of the sentinel lymph nodes and the lymphadenectomy specimen.

RESULTS

We included 19 patients, with a final diagnoses of endometrioid carcinoma (18 cases) and endometrial stromal sarcoma (1 case). At least one sentinel lymph node was identified in 17 of them (89.5% detection rate). Twenty-nine sentinel lymph nodes were identified during surgery, all of them negative for neoplastic infiltration. No metastatic invasion was found in the pelvic lymphadenectomy specimens as well.

CONCLUSIONS

The sentinel lymph node biopsy technique seems to be a reliable tool in nodal staging of endometrial cancer at early stages, with an acceptable detection rate and high histological correlation. The low prevalence of lymphatic spread in this group of patients and the encouraging results obtained could make the sentinel lymph node an alternative to routine complete lymphadenectomy.

[Prevalence of micrometastases and isolated tumor cells in the sentinel node at early stage breast cancer]

AIM

To analyze the prevalence of isolated tumor cells (ITC) and micrometastases in the sentinel node of early stage breast cancer.

MATERIAL AND METHODS

A total of 234 patients diagnosed of breast cancer, stages T1 or T2, with no axillary involvement detected by palpation or ultrasound-FNA, were studied. The sentinel node (SN) was identified by lymphoscintigraphy and removed in the operating room. Serial sections and immunohistochemical staining were then performed, classifying them as negative (SN-), negative with ITC (SN-ITC), positive with micrometastases (SN+mic) and positive with macrometastases (SN+mac). A complete axillary lymphadenectomy (CAL) was carried out in those cases with micro- or macrometastases, the former being classified as negative (CAL-), positive with micrometatases (CAL+mic), and positive with macrometastases (CAL+mac). The follow-up ranged from 6-71 months.

RESULTS

ITC were found in 12 patients (5.1%) and micrometastases in 24 (10.3%). Thus, a total of 36 patients were affected by some of these conditions (15.4%). In the group with micrometastases, the result of CAL was CAL- in 19/24 (79.1%), CAL+mic in 2 (8.3%) and CAL+mac in 3 (12.5%). No axillary recurrences have occurred up to date.

CONCLUSIONS

ITC and micrometastases were found in the sentinel node in a significant percentage of patients in the early stages of breast cancer. The low percentage of further axillary invasion in the group of micrometastases may open up the possibility of avoiding CAL in favor of other adjuvant treatments (chemotherapy, radiotherapy).

[18F-FDG PET/CT with retrograde filling of the urinary bladder in the assessment of malignant pelvic disease]

AIM

To assess the role of PET/CT with retrograde filling of urinary bladder (RFUB) in the assessment of pelvic malignancy in patients with urothelial or gynecological tumors.

MATERIAL AND METHODS

A retrospective longitudinal analysis based on 62 studies belonging to 52 patients was performed. All of them had a history of pelvic malignancy (29 urothelial and 23 gynecological) and 42 had undergone previous treatments. All patients underwent a standard PET/CT protocol. Inclusion criteria were radiological alterations in pelvic organs or increased urinary activity of (18)F-FDG that hindered evaluation of the pelvic structures. Pathological pelvic locations were assessed as the additional value of PET/CT with RFUB. The pathologic lesions were histologically or clinically evaluated with a minimum follow-up of 12 months.

RESULTS

Pelvic malignancy was confirmed in 33 cases, 16 of which were of urothelial origin. A total of 35/62 studies showed a pathologic PET/CT in pelvis, 4 of them were false positive and 2 false negative. In 19 cases, malignancy was detected in the bladder wall, 16 of which were true positive. No false negative was detected. Regarding standard imaging acquisition, RFUB helped to confirm or rule out bladder and/or gynecological disease in 54 cases.

CONCLUSION

Retrograde bladder filling is a highly recommended technique in the assessment of malignant pelvic disease, especially of bladder origin.

[Utility of PET-CT on radiotherapy planning of head and neck cancer. Our initial experience]

OBJECTIVE

To describe the methods used for the incorporation of FDG-PET-CT on radiotherapy planning of patients with head and neck cancer and also to evaluate the impact of FDG-PET-CT on staging and tumor volume definition.

MATERIAL AND METHODS

A prospective study in which 20 patients with head and neck tumor submitted for radiotherapy treatment were included. All underwent a whole body PET- CT (GE DSTE 16) for staging and restaging, also acquiring an additional 3h delayed PET image with diagnostic CT parameters for planning. A CT scan with diagnostic protocol, tabletop available for radiotherapy treatment and the same personalized head-shoulder mask were used in the latter. Lymph node involvement and/or distant involvement were evaluated, considering the changes in staging. We also evaluated the differences in volumes obtained between the different techniques. The threshold value used for delineating PET gross tumor volume (GTV) was empirically established and ranged from 20-40% of the maximum SUV.

RESULTS

Radiotherapy planning was performed with PET-CT in 20 patients between October 2007 to September 2008. A total of 29 lesions (18 primary lesions because 2 patients were excluded as no tumor was observed on the PET CT images, and 11 nodes). The most frequent location was oropharynx (5 patients). Mean maxSUV of the 29 lesions was 14.4 (range 5.0 and 26.4). No statistically significant differences were found between the GTV PET and GTV CT (mean 21.9cm³ and 19.3cm³, respectively). PET-CT modified the staging in 20% of the patients, with a diagnostic and therapeutic impact of 50 and 25%, respectively.

CONCLUSION

The incorporation of PET-CT in routine radiotherapy planning is a promising technique that requires close collaboration between the nuclear medicine and radiotherapy oncology departments. PET-CT achieves better staging in patients and has a significant diagnostic and therapeutic impact. The use of the hybrid technique avoids problems arising from co-registry as well as a second examination for planning with the consequent advantage for the patient. Nonetheless, more prospective and randomized studies with pathology specimens are needed to evaluate the real impact in the tumor volume definition.

[PET-CT with intravenous contrast in the evaluation of patients with lymphoma. Contribution to diagnostic indications]

AIM

To define the utility of intravenous contrast administration in the PET-CT (PET-CTc) in patients with lymphoma in order to determine its possible indications.

MATERIAL AND METHODS

78 patients with lymphoma were prospectively evaluated. All underwent simultaneous PET-CTc scans in a hybrid system for staging (8), evaluation of response to treatment (29), suspicion of recurrence (9) and complete remission control (48). The PET scan was acquired by a conventional method and the diagnostic CT scan was performed according to radiological protocol. Both examinations were evaluated blinded and independently, analyzing 28 anatomical locations in order to determine the degree of agreement. Final diagnosis was established by the clinician based on the histological study, results of other diagnostic techniques or clinical follow-up.

RESULTS

The final result of both techniques were concordant in 87/94 studies (92.5%). A total of 158 (36 FP) pathological locations were detected with PET-CT and 189 (71 FP) with CTc, with 72 locations being discordant between both techniques. Global sensitivity, specificity, PPV and NPV were 93%, 98%, 77% and 99%; and 94%, 97%, 62% and 99%, respectively.

CONCLUSIONS

Administration of intravenous contrast does not seem to provide any advantage in the determination of nodal and extranodal disease in lymphoma patients. The low prevalence of disease probably accounts for the limited PPV of both techniques. An increase of our sample size, with a greater homogeneity of the groups, should offer more reliable results.

[Usefulness of ventricular function values obtained using post-stress gated-SPECT in a diabetic population with clinical suspicion of ischaemic heart disease]

OBJECTIVE

To assess the clinical usefulness of left ventricular function values obtained using post-stress myocardial perfusion gated-SPECT in diabetic patients with suspected ischaemic heart disease (IHD).

MATERIALS AND METHODS

Sixty-one patients with diabetes mellitus (DM), with clinical suspicion of IHD and no previous history of heart disease were studied. Ergometric or pharmacological post-stress myocardial perfusion gated-SPECT was performed on all patients. The relationship between the ejection fraction values and ventricular volumes, and the perfusion study results, final diagnosis, severity of the perfusion defects and the clinical evolution was studied. The mean follow-up time was 14 months. RESULTS; All the ventricular function values independently showed significant differences between the groups with a normal and pathological perfusion study, and between groups with a final diagnosis of IHD and non-IHD. After multivariate logistic regression, the end-diastolic volume (EDV) was the only value which showed a statistical association with the pathological perfusion study, its severity and the final diagnosis of IHD. No statistical association was observed between the ventricular function values and the occurrence of cardiac events.

CONCLUSIONS

All the ventricular function values obtained by gated-SPECT added diagnostic information to the post-stress myocardial perfusion study in the diabetic population with suspected IHD; however, only EDV showed a statistical association with the pathological perfusion study, severity of defects and the final diagnosis of IHD.

[Study of physician satisfaction as a quality criterion in Nuclear Medicine]

OBJECTIVE

To determine the perception and satisfaction level of referring physicians requesting scans as final users of the Nuclear Medicine Department.

MATERIAL AND METHODS

A self-administered questionnaire was designed; it was composed of 10 closed questions (5 categorised and 5 with numerical scale) and 3 open questions. The indicators evaluated were: physician's information about available tests, test indications and diagnostic information, accessibility, delay in the examination and reception of the diagnostic report, usefulness of diagnostic information and overall satisfaction with the department. Two hundred and fifteen questionnaires were sent.

RESULTS

Seventy eight questionnaires were returned, so the response index was 36.3 %. The 44.6 % of physicians surveyed considered that they had sufficient information about the tests and 59.5 % were satisfied with the indications and diagnostic information. The accessibility was 7 or more out of 10 for 78.5 %. The 64.9 % of physicians considered the delay in performing examinations to be correct but the satisfaction was lower in the delay between performance and reception of the diagnostic report. The diagnostic information was considered useful by 81.9 % and relevant in the management of patients by 70.5 % of the participants surveyed. The overall satisfaction was > or = 7 out of 10 in 86.8 %.

CONCLUSIONS

Overall satisfaction was high, although the level of knowledge about available tests and the delay between test performance and report reception could be improved.

[Are bone scintigraphy examinations requested in oncologic patients according to established indications?]

OBJECTIVE

To determine the percentage of bone scintigraphy examinations (BS) requested according to established indications and to assess the clinical impact of the scintigraphic results.

MATERIAL AND METHODS

A retrospective study was performed including BS in 117 patients (70 women and 47 men) carried out in our department during the year 2001. All patients had a primary extraosseous malignancy. The correctness of the indication of each study requested was analyzed according to established criteria from the literature. BS results were classified as positive, negative, and equivocal for metastatic disease.

RESULTS

96 out of the 117 BS were performed in patients affected with the most prevalent primary malignancies: breast (57), prostate (21), and lung (18). The remaining studies were included in a miscellaneous group (gynecological [3], colorectal [4], oropharyngeal [4], and renal malignancies [4]; lymphoma [2], melanoma [2], hemangioendothelioma [1]; and cancer of the bladder [1] or pancreas [1]). Ninety-nine (85 %) of the 117 BS performed met the criteria for appropriate indication. The indication was correct in 75 % of breast, 90 % of prostate (19/21), and 100 % of lung cancers. The indication was correct in 90 % of the cases in the miscellaneous group. BS were positive in 21 patients (20 of which were confirmed). BS were equivocal in 24 patients (in 5 of whom bone metastases were confirmed). BS were negative in 72 patients (one of whom had bone metastases). The BS findings changed staging in 9 % (9/99) of the correctly indicated cases.

CONCLUSION

Most BS (85 %) were indicated according to the established criteria and the clinical impact was greater in this group.